How do I put new Rootfs in LTIB (Using imx53 START-R QSB)

[RodneyFulk]

After following the directions in the document:

Ubuntu 11.10 64-bit host i.MX53 START_R LTIB 11.09.01

I am able to successfully build an image for my Start-R board and have test run the minimal FS that comes with this.

Now I am trying to figure out how to replace the rootfs that is normally included in this package with 12.04.

I want to replace the actual FS that is in the ltib directory so I can properly compile it there.

What I have tried so far is to write the linaro 12.04 for the older non-start-r board to an SDCARD and then copy this back off into a directory I am calling rootfs_new.

I then renamed the old rootfs to rootfs_old, renamed my new one to rootfs and tried to rebuild my ltib and it failed on various permissions errors. I am guessing I need to change some permissions but when I looked they seem to be the same between the two file systems.

I realize I could just write the new kernel to the SDCARD but I want my build environment to be the same as the environment I will be using. I am sure I am missing something simple but I am not figuring this out.

Also, could I use ANY ARM 12.04 image? I recently bought a saber lite imx6 board and I want to end up with both boards running the same operating system for a project I am working on.

Thank you for the help

[jimmychan · Accepted solution]

You can try to boot up the board using the NFS? so you just change the link (linux command : ln -s) to different RFS folder.

This document may useful for you.

[RodneyFulk]

I am trying to understand how to do this manually first. Once I have better understanding how to do it manually I will likely be making much use of NFS when developing drivers and such but I want to make sure I understand how to do it on the SDcard first.

[RodneyFulk]

Ok, I am still trying to sort out how to incorporate a different rootfs. Since writing this original message I figured out that the rootfs that is in the ltib is actually configured during the compile of the images so just copying a filesystem over the top of the current rootfs in the ltib library will not work. I really only need to compile the kernel to make changes for my drivers and such once I have a rootfs that works.

My impression is that I SHOULD be able to take ANY ARM binary rootfs and be able to use it with the imx53 or any of the imx6 boards. The only difference is related to the kernel and any drivers compiled into it. With the standard LTIB build does the kernel compile any modules or anything that need to reside on the rootfs or is everything stored in the kernel space saved on the SDCard prior to the rootfs partition?

At some point I will be playing around with trying to speed up my bootup by compiling the kernel with modules and delay loading the non critical modules until after the display is running. I need to know where those modules are stored in the file system so I can make sure they make it to the rootfs as intended.

Thanks for any help on this!

Learning something new every day!

So basically my impression is that I should be able to take for instance a ubuntu 12.04 rootfs and copy it onto both my imx6 sabre lite board and my imx53qsb and it will be usable once I apply the Boundary bootscripts that are required for the sabre lite imx6 board and any kernel modules required by the board I am running it on?

Rodney